This invention relates to a steering clutch and brake for controlling the travelling of a tractor such as bulldozer, and more particularly to a control valve for a hydraulically actuated steering clutch and brake.
Conventional control valves for a steering clutch and brake of this type are either actuated by independent operating rods, respectively or actuated in interlocked relationship by a common operating rod, but in either case, the steering clutch and the steering brake are actuated by means of respective control valves.
Therefore, the conventional control device is disadvantageous in that a separate operating rod is required for each of the steering clutch and the steering brake so that the entire structure becomes complicated, and the respective operating rods have to be adjusted in length in such a manner that after the steering clutch is released, the steering brake is controlled.